Abu Mansur al-Baghdadi in Manaqib al-Shafi`i and Naqd Abi `Abd Allah
al-Jurjani fi Tarjih Madhhab Abi Hanifa relates the following example of
the Imam's perspicuity at an early age:

Al-Shafi`i was sitting at Malik's feet one day when a man came in and
said: "I sell turtle-doves, and one of my customers returned one of them
to me today, saying that it does not coo, so I swore to him on pain of
divorce that my turtle-dove coos all the time!" Malik said: "You have
divorced your wife and are not to approach her." Al-Shafi`i was fourteen
at the time. He said to the man: "Which is more, your turtle-dove's cooing
or its silence?" The man said: "Its cooing."
Al-Shafi`i said: "Consider
your marriage valid, and there is no penalty on you." Whereupon Malik
frowned at him saying: "Boy! How do you know this?" Al-Shafi`i replied:
"Because you narrated to me from al-Zuhri, from Abu Salama ibn `Abd
al-Rahman, from Umm Salama, that Fatima bint Qays said: 'O Messenger of
Allah! Abu Jahm and Mu`awiya have both proposed to me.'
The Prophet replied: 'As for Mu`awiya he is penniless,
and as for Abu Jahm he does not put down his staff from his shoulder [from
travel].'1 Meaning: in most of his states; for the Arabs declare the more
frequent of two actions [exclusively of the other] because of its
constancy. And since the cooing of this man's turtledove is more than its
silence, I declared it constant in its cooing." Malik was pleased at his
reasoning.2